The present disclosure relates to an electrophotographic image forming apparatus.
In an electrophotographic image forming apparatus, after a photoconductive drum is charged to negative by a charging roller, a negatively-charged part of the photoconductive drum is applied with a light beam, which forms a latent image. The latent image is developed by a developer that is supplied from a developing roller and a feeding roller, and a developer image formed by the development is transferred on paper by a transfer roller.
In the case where the image forming apparatus is a printer forming a color image, it is necessary to strictly control an amount of the developer to be transferred on paper in order to faithfully reproduce the color image. For example, in Japanese Unexamined Patent Application Publication No. 2004-29681, an image forming apparatus is disclosed in which density of a developer of a patch pattern printed on a transfer belt is measured, and density correction of the developer is performed by controlling a process condition, based on density data obtained through the measurement.